1. Technical Field
The present invention relates to a printing apparatus and a power supply unit for a printing apparatus.
2. Related Art
In recent years, printing apparatuses tend to have more functionality. For example, the following multifunctional printing apparatus has been developed. The multifunctional printing apparatus has a printing function of executing a printing process of forming an image on a recording medium (hereinafter merely referred to as “medium” in some cases) and at least one function among functions that exclude the printing function and are a copy function of executing a copy process of copying an image printed on a recording medium, a scanner function of executing a reading process of reading an image printed on a recording medium, generating digital image data indicating the read image, and storing the image data in a storage device or the like, a facsimile transmission function of executing a facsimile transmission process of transmitting the image data obtained by reading the image printed on the recording medium or the like to another printing apparatus (an example of an “external device”) via a network, a facsimile reception function of executing a facsimile reception process of receiving image data transmitted from another printing apparatus and forming an image on a recording medium based on the received image data, and the like (refer to, for example, JP-A-2008-1887269).
In recent years, printing apparatuses tend to have high functionality, and the definition and speed of printing in printing processes tend to be increased (refer to, for example, JP-A-9-314915).
In general, if a printing apparatus has more functionality, and the definition and speed of printing of the printing apparatus are increased, the amount of power to be consumed by the printing apparatus increases. If the amount of power to be consumed by the printing apparatus increases, the amount of heat generated by a power supply unit, which is included in the printing apparatus and configured to convert an alternating voltage supplied from a commercial alternating power supply to a direct-current voltage able to be used in the printing apparatus, increases. Thus, if the printing apparatus has more functionality, and the definition or speed of the printing of the printing apparatus is increased, the temperature of the power supply unit included in the printing apparatus is likely to change to a high temperature, compared with the case where the printing apparatus is a monofunctional printing apparatus or the case where printing is executed with low definition or at a low speed. If the temperature of the power supply unit continues to be high, a failure may occur in the power supply unit, and the printing apparatus may not normally operate.